UnratedFix available
libgit2 vulnerability
Type: advisorySources: OSV
It was discovered that libgit2 incorrectly handled IP address SubjectAltName verification in TLS certificate validation. A remote attacker with a CA-trusted certificate could possibly use this issue to perform a machine-in-the-middle attack, leading to the exposure of sensitive information.
- Products
- libgit2
- Affected versions
- 1.5.1+ds-1ubuntu1, 1.7.1+ds-2ubuntu1, 1.7.2+ds-1ubuntu1, 1.7.2+ds-1ubuntu2, 1.7.2+ds-1ubuntu3, 1.7.2+ds-1ubuntu3.1, 1.7.2+ds-1ubuntu3.2, 1.9.0+ds-2ubuntu2, 1.9.1+ds-1ubuntu1, 1.9.1+ds-1ubuntu1.1, 1.9.1+ds-1ubuntu1.2
- Fixed versions
- 1.7.2+ds-1ubuntu3.3, 1.9.1+ds-1ubuntu1.3
- CVEs
- CVE-2026-53583
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 10:37 UTC · Revision 1
Source evidence
It was discovered that libgit2 incorrectly handled IP address SubjectAltName verification in TLS certificate validation. A remote attacker with a CA-trusted certificate could possibly use this issue to perform a machine-in-the-middle attack, leading to the exposure of sensitive information.
osv:USN-8907-1
libgit2
Fixed versions: 1.7.2+ds-1ubuntu3.3
libgit2
Fixed versions: 1.9.1+ds-1ubuntu1.3
Complete source record
{
"id": "3df18e52f92516a13886cf768ebfc79d324b72911f007cccb793bb2e5ee16389",
"url": "https://osv.dev/vulnerability/USN-8907-1",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "libgit2 vulnerability",
"summary": "It was discovered that libgit2 incorrectly handled IP address SubjectAltName verification in TLS certificate validation. A remote attacker with a CA-trusted certificate could possibly use this issue to perform a machine-in-the-middle attack, leading to the exposure of sensitive information.",
"evidence": "osv:USN-8907-1",
"products": [
{
"name": {
"value": "libgit2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.7.2+ds-1ubuntu3.3",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "1.5.1+ds-1ubuntu1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.1+ds-2ubuntu1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.2+ds-1ubuntu1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.2+ds-1ubuntu2",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.2+ds-1ubuntu3",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.2+ds-1ubuntu3.1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.2+ds-1ubuntu3.2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "libgit2",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.9.1+ds-1ubuntu1.3",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "1.9.0+ds-2ubuntu2",
"evidence": "/affected/1/versions"
},
{
"value": "1.9.1+ds-1ubuntu1",
"evidence": "/affected/1/versions"
},
{
"value": "1.9.1+ds-1ubuntu1.1",
"evidence": "/affected/1/versions"
},
{
"value": "1.9.1+ds-1ubuntu1.2",
"evidence": "/affected/1/versions"
}
]
}
],
"severity": "unknown",
"structured": {
"id": "USN-8907-1",
"aliases": [
"USN-8907-1"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.7.2+ds-1ubuntu3.3"
}
]
}
],
"package": {
"name": "libgit2",
"purl": "pkg:deb/ubuntu/libgit2?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"1.5.1+ds-1ubuntu1",
"1.7.1+ds-2ubuntu1",
"1.7.2+ds-1ubuntu1",
"1.7.2+ds-1ubuntu2",
"1.7.2+ds-1ubuntu3",
"1.7.2+ds-1ubuntu3.1",
"1.7.2+ds-1ubuntu3.2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8907-1.json",
"cves_map": {
"cves": [
{
"id": "CVE-2026-53583",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
}
],
"ecosystem": "Ubuntu:24.04:LTS"
}
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libgit2-1.7",
"binary_version": "1.7.2+ds-1ubuntu3.3"
},
{
"binary_name": "libgit2-fixtures",
"binary_version": "1.7.2+ds-1ubuntu3.3"
}
],
"availability": "No subscription required"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.9.1+ds-1ubuntu1.3"
}
]
}
],
"package": {
"name": "libgit2",
"purl": "pkg:deb/ubuntu/libgit2?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"1.9.0+ds-2ubuntu2",
"1.9.1+ds-1ubuntu1",
"1.9.1+ds-1ubuntu1.1",
"1.9.1+ds-1ubuntu1.2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8907-1.json",
"cves_map": {
"cves": [
{
"id": "CVE-2026-53583",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
}
],
"ecosystem": "Ubuntu:26.04:LTS"
}
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libgit2-1.9",
"binary_version": "1.9.1+ds-1ubuntu1.3"
},
{
"binary_name": "libgit2-fixtures",
"binary_version": "1.9.1+ds-1ubuntu1.3"
}
],
"availability": "No subscription required"
}
}
],
"modified": "2026-10-09T01:57:56.992465151Z",
"provider": "osv",
"upstream": [
"CVE-2026-53583",
"UBUNTU-CVE-2026-53583"
],
"references": [
"https://ubuntu.com/security/notices/USN-8907-1",
"https://ubuntu.com/security/CVE-2026-53583"
]
},
"related_cves": [
{
"value": "CVE-2026-53583",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 108249,
"published_at": "2026-10-08T13:40:27+00:00"
}